<template>
  <div class="header">
    <!-- 折叠按钮 -->
    <div class="collapse-btn" @click="collapseChage">
      <i class="el-icon-menu"></i>
    </div>
    <div class="logo">后台管理系统</div>
    <div class="header-right">
      <div class="header-user-con">
        <!-- 全屏显示 -->
        <div class="btn-fullscreen" @click="handleFullScreen">
          <el-tooltip effect="dark" :content="fullscreen?`取消全屏`:`全屏`" placement="bottom">
            <i class="el-icon-rank"></i>
          </el-tooltip>
        </div>
        <!-- 用户头像 -->
        <div class="user-avator"><img src="@/assets/img/img.jpg"></div>
        <!-- 用户名下拉菜单 -->
        <el-dropdown class="user-name" trigger="click" @command="handleCommand">
                    <span class="el-dropdown-link">
                        {{username}} <i class="el-icon-caret-bottom"></i>
                    </span>
          <el-dropdown-menu slot="dropdown">
            <a href="http://blog.gdfengshuo.com/about/" target="_blank">
              <el-dropdown-item>关于作者</el-dropdown-item>
            </a>
            <a href="https://github.com/lin-xin/vue-manage-system" target="_blank">
              <el-dropdown-item>项目仓库</el-dropdown-item>
            </a>
            <el-dropdown-item divided  command="logout">退出登录</el-dropdown-item>
          </el-dropdown-menu>
        </el-dropdown>
      </div>
    </div>
  </div>
</template>
<script>
import bus from '@/api/bus';
export default {
  data() {
    return {
      collapse: false,
      fullscreen: false,
      name: '没登录你咋进来的',
      message: 2
    }
  },
  computed:{
    username(){
      let username = localStorage.getItem('username');
      return username ? username : this.name;
    }
  },
  methods:{
    // 用户名下拉菜单选择事件
    handleCommand(command) {
      if(command === 'logout'){
        localStorage.removeItem('username')
        this.$router.push('/login');
      }
    },
    // 侧边栏折叠
    collapseChage(){
      this.collapse = !this.collapse;
      bus.$emit('collapse', this.collapse);
    },
    // 全屏事件
    handleFullScreen(){
      let element = document.documentElement;
      if (this.fullscreen) {
        if (document.exitFullscreen) {
          document.exitFullscreen();
        } else if (document.webkitCancelFullScreen) {
          document.webkitCancelFullScreen();
        } else if (document.mozCancelFullScreen) {
          document.mozCancelFullScreen();
        } else if (document.msExitFullscreen) {
          document.msExitFullscreen();
        }
      } else {
        if (element.requestFullscreen) {
          element.requestFullscreen();
        } else if (element.webkitRequestFullScreen) {
          element.webkitRequestFullScreen();
        } else if (element.mozRequestFullScreen) {
          element.mozRequestFullScreen();
        } else if (element.msRequestFullscreen) {
          // IE11
          element.msRequestFullscreen();
        }
      }
      this.fullscreen = !this.fullscreen;
    }
  },
  mounted(){
    if(document.body.clientWidth < 1500){
      this.collapseChage();
    }
  }
}
</script>
<style scoped>
.header {
  position: relative;
  box-sizing: border-box;
  width: 100%;
  height: 70px;
  font-size: 22px;
  color: #fff;
}
.collapse-btn{
  float: left;
  padding: 0 21px;
  cursor: pointer;
  line-height: 70px;
}
.header .logo{
  float: left;
  width:250px;
  line-height: 70px;
}
.header-right{
  float: right;
  padding-right: 50px;
}
.header-user-con{
  display: flex;
  height: 70px;
  align-items: center;
}
.btn-fullscreen{
  transform: rotate(45deg);
  margin-right: 5px;
  font-size: 24px;
}
.btn-bell, .btn-fullscreen{
  position: relative;
  width: 30px;
  height: 30px;
  text-align: center;
  border-radius: 15px;
  cursor: pointer;
}
.btn-bell-badge{
  position: absolute;
  right: 0;
  top: -2px;
  width: 8px;
  height: 8px;
  border-radius: 4px;
  background: #f56c6c;
  color: #fff;
}
.btn-bell .el-icon-bell{
  color: #fff;
}
.user-name{
  margin-left: 10px;
}
.user-avator{
  margin-left: 20px;
}
.user-avator img{
  display: block;
  width:40px;
  height:40px;
  border-radius: 50%;
}
.el-dropdown-link{
  color: #fff;
  cursor: pointer;
}
.el-dropdown-menu__item{
  text-align: center;
}
</style>
